sedimentary
River Stone (likely Quartzite or Chert)
Sedimentary rock composed of Silicon Dioxide (SiO2)
Hardness: 6.5-7 on Mohs scale; Color: tan, yellow-brown with dark inclusions; Luster: dull to waxy; Structure: microcrystalline/cryptocrystalline; Cleavage: none, conchoidal fracture.
- Hardness
- 6
- Color
- tan, yellow-brown with dark inclusions
- Luster
- dull to waxy
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: tan, yellow-brown with dark inclusions; Luster: dull to waxy; Structure: microcrystalline/cryptocrystalline; Cleavage: none, conchoidal fracture.
Formation & geological history
Formed through the accumulation of silica-rich sediments or the metamorphism of sandstone. These specimens have been smoothed and rounded by long-term hydraulic action in riverbeds over thousands to millions of years.
Uses & applications
Commonly used in landscaping, construction aggregate, decorative garden features, and sometimes as tumbling media for rock hobbyists.
Geological facts
River rocks like these are often transported hundreds of miles from their original source by water flow, which acts as a natural rock tumbler, removing sharp edges and leaving a smooth finish.
Field identification & locations
Identify by its smooth, water-worn texture and rounded shape. Found globally in current or ancient riverbeds, deltas, and glacial deposits. Collectors value them for their tactile shape.
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